What can the SysOps Administrators for each company do to set up network routing?
Each Administrator should create a custom routing table that points to the other company’s internet gateway public IP address.
Both Administrators should set up a NAT gateway in a public subnet in their respective VPCs. Then. using the public IP address from the NAT gateway, the Administrators should enable routing between the two VPCs.
Both Administrators should install a 1 Gbps AWS Direct Connect circuit in their respective environments. Then, using the AWS Management Console, the Administrators should create an AWS Direct Connect routing requests to enable connectivity.
One Administrator should create a VPC peering request and send it to the other Administrator’s account. Once the other Administrator accepts the request, update the routing tables to enable traffic.
Explanations:
Creating a custom routing table that points to the other company’s internet gateway public IP address will not allow private communication between the VPCs. The routing should be set up between the VPCs directly.
A NAT gateway allows private instances to access the internet, but it is not needed for inter-VPC communication. VPC peering or other solutions are better suited for direct traffic between VPCs.
AWS Direct Connect is a dedicated network connection and is more complex and costly than necessary for this situation. VPC peering is the appropriate solution for connecting the VPCs in this scenario.
VPC peering is the best solution for enabling direct communication between VPCs in different accounts. One administrator creates a VPC peering connection, which the other accepts, and then the routing tables are updated to allow traffic.
I reckon the answer is:
One Administrator should create a VPC peering request and send it to the other Administrator’s account. Once the other Administrator accepts the request, update the routing tables to enable traffic.